I created a module in frontend (Website). I have a form and some fields are dates. I try to use a datepicker, but if the user logged have no access to edit Website, I got "$(...).datepicker is not a function"on my browser console. What is the problem?

Finally I found a part of my problem. It is because jQuery.ui look is not enable with some rights. I added jquery-ui in my template. Now, it is ok for all users instead the Admin. Now the admin got this error message in browser console: $(...).zIndex is not a function